The 15th International Conference of International Academy of Physical Sciences Dec 9 - 13, 2012, Pathumthani, Thailand Preparation of alumina – graphene composites by Long Pulsed Laser Ablation Voranuch Thongpool 1,a , Akapong Phunpueok 1,b ,Veeradate Piriyawong 2,3, c , Supanee Limsuwan 2,d , and Pichet Limsuwan 2,3, e 1 Division of Physics, Faculty of Science and Technology Rajamangala University of Technology Thanyaburi, 39 M.1 Klong 6, Thanyaburi, Pathumthani 12110, Thailand 2 Department of Physics, Faculty of Science King Mongkut’s University of Technology Thonburi, 126 Pracha-Utid Road, Bangmod, Thoongkru, Bangkok 10140, Thailand 3 Thailand Center of Excellence in Physics, CHE, Ministry of Education, Bangkok 10400, Thailand. a nuchphysics@gmail.com, b aumaum18@hotmail.com , c changphysics@hotmail.com, d supanee.lim@kmutt.ac.th, e opticslaser@yahoo.com Abstract In this work, the alumina - graphene composites were fabricated by laser ablation of graphite target in deionized water with alumina nanoparticles suspension using pulsed Nd:YAG laser. The mechanism of the graphene formation is derived from the insertion of alumina nanoparticles into the interlayer spacing of graphite which expand during laser heating. The synthesized alumina - graphene composites were characterized by field emission scanning electron microscope (FESEM), EDX, and UV-visible spectrophotometer. Keyword: Laser ablation, graphene, alumina 1. Introduction Graphene is a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice which was discovered in 2004 by Novoselov and Geim [1]. Graphene has many advantageous characteristics including low sheet resistance, high optical transparency and excellent mechanical properties that make it an ideal material for essential studies as well as for potential applications. For this reason makes many researcher interested in the applications of graphene such as an electrode material in transistors [2], light- emitting diodes [3], solar cells [4] and flexible devices [5]. Several methods have been used to synthesize graphene such as chemical vapor deposition (CVD) [6], epitaxial growth on electrically insulating surfaces [7], electric arc discharge [8], solution-based chemical reduction of graphene oxide [9] and laser ablation in liquid [10]. Among these reported methods, laser ablation in liquid seems to be the most simple preparation and inexpensive approach to synthesize graphene because it does not require a vacuum system. In this method, the laser beam is focused the target settled in the liquid. The graphenes are suspended in the liquid medium, instead of fuming in the air. In this study, the preliminary results on our work were reported. Graphene – liked sheets were synthesized via laser ablation of graphite target in alumina nanosol. The morphology and chemical composition of graphene – liked sheets were investigated by field emission scanning electron microscopy (FESEM) and EDX technique. The optical property was examined by UV-visible spectroscopy. 2. Experimental Preparation of aluminium and graphite target The aluminium and graphite target were obtained from pressing powders under a hydraulic press. The consolidation pressure was 200 bars. Fig. 1 shows the process of consolidation of graphite powder. Figure 1 Consolidation of graphite powder with hydraulic press - 139 -